Quadrature Amplitude Modulation is used with various different structures as 8QAM, 16QAM, 64QAM, 128QAM, 256QAM, but there are functional divergences and replacement. As the QAM range enhances, so the space between the distinct points on the constellation plot step-downs and there is a good chance of data errors being acquainted. To make use of the higher order QAM formatting, the channel must have an extremely superior Eb/No unless data errors will confront. Consequently there is a balance to be made between the data rate, QAM modulation order, power and the acceptable bit error rate. Low power modulators are most efficient for wireless communication. The advantage of using QAM is that it is a higher order form of modulation and as a result, it is able to carry more bits of information per symbol. By selecting a higher order format of QAM, the data rate of a link can be improved. The conventional 64QAM devours more power and area. In this work, three new approaches are introduced for 64QAM modulator. In the first approach, the look up table is used to store sine and cosine generated data to reduce the power consumption and area utilization. In the second approach, information bit stream is modulated with sine and cosine waves generated by iterative algorithm to minimize power and area requirement. In the third approach, the phase data generated by using previous method is stored in the memory. This stored phase data is selected according to the input message stream, this approach to 64QAM modulator consumes less power and area in comparison with the conventional modulator. The work is analyzed, synthesized and compared in 180nm, 90nm and 45nm CMOS technology using Cadence software.
Volume 11 | 03-Special Issue
Pages: 1866-1873